Tuesday, October 23, 2012

Iowa Wants to be the Saudi Arabia of Advanced Biofuels

Iowa is a prolific producer of biomass. It has also long been a focus of innovative design and engineering.

Here is the basic plan devised by Iowa State University engineers:

The Iowa State idea calls for biomass to be transported to small, local fast pyrolysis plants that would convert crop biomass into liquid bio-oil. The bio-oil would be easily transported to bigger, regional facilities where it could be gasified and processed into transportation and boiler fuels.

First, biomass is fed into a fast pyrolysis machine where it's quickly heated without oxygen.The end product is a thick, brown oil that can be divided and further processed into fuels. Researchers sometimes describe bio-oil as densified biomass that's much easier to handle and transport than raw biomass.

Second, the bio-oil is sprayed into the top of the gasifier where heat and pressure vaporize it to produce a combination of (mostly) hydrogen and carbon monoxide that's called synthesis gas.

That gas can be processed into transportation fuels. It can also be used as boiler fuel to create the steam that turns turbines to produce electricity.

"We hope to be able to use cellulosic biomass as opposed to using corn grain for the production of fuels," said Robert C. Brown, the director of Iowa State's Bioeconomy Institute, an Anson Marston Distinguished Professor in Engineering and the Gary and Donna Hoover Chair in Mechanical Engineering. "This helps us move toward cellulosic biofuels." _PO

Iowa State's basic plan helps to solve some of the problems involved in converting biomass to advanced biofuels. But this approach will remain too expensive to compete with cheap natural gas for at least the next several years, if not the next few decades.

Even worse, the Iowa State plan does not address one of the biggest weaknesses in most biomass to biofuels approaches: The cost of collecting the biomass and bringing it together for preprocessing.

There are several viable alternatives to choose from, in solving that and other similar problems. But as long as natural gas remains cheap and readily available, it is unlikely that even the best of biomass to liquids approaches will be able to compete on a large and global scale.

Even so, these technologies should be perfected for many reasons: In geographically isolated regions and islands, hydrocarbon fuels can be extremely expensive. In such areas, advanced BTL may prove viable.

More, as scalable gas-cooled nuclear reactors become available, the cost of BTL will drop due to the availability of cheap, high temperature heat. Finally, natural gas costs are certain to rise sooner or later. It would be best to have your BTL technology ready for scaling up, when that happens.